Brake



Patented Oct. 25, 1927.

UNITED STATES FRANK WILKINSON, or NEW CASTLE, INDIANA, AND

KEE, 'CONSIN,

WERNER LEHMAN, F MILWAU- WISCONSIN, ASSIGNORS TO BUCYRUS COMPANY, OF SOUTH MILWAUKEE, WIS- A CORPORATION OF WISCONSIN.

BRAKE.

Application filed April 11, 1923. Serial No. 631,270.

Uur invention relates to new anduseful improvements in band brakes, and has for its principal object to provide a means for taking up and releasing the, slack 1n the dead-end of brake-bands.

Heretofore, the chief practical operating difliculty with band brakes, particularly. when actuated by a foot lever, "has been that so large a part of the travel of the lever has had to be devoted merely to taking up and releasing the slack in the brake-band; thus either requirin a very short lever with con sequent loss 0 leverage, or requiring too much travel of thelever for convenient footoperation.

A-further difficulty has been that the limiited play of the brake lever has never permitted a sufiicient slacking off of'the brakeband to enable adequate cooling of the band 2 between its successive applications, and this fact has resulted in great and undue wear on both band and drum.

. It is our object to eliminate these troubles by providing an automatic take-up and release of the slack, so that a very long lever can be employed, the solely to determining the degree of tension in the band. This long lever permits a very delicate control of the braking operation,

without undue foot-travel. The automatic take-up and release permits the complete slacking away of the brake-band when not in use, thus providing ample' space for cooling currentsof air. Other advantages of my design will naturally suggest then'iselves as the description progresses. It is within the province of the disclosure to improve generally and to enhance the utility of devices of that type to which the invention appertains. With these general objects in view, the invention resides in the novel features of construction, combination and arrangement of parts which will be hereinafter more particularly described and claimed, and shown in the accompanying view of our apparatus, partly in section.

Referring more particularly to this drawing, it will be seen that 1 represents a crosssection of the shaft to be braked. Keyed to 5 this shaft is a brake-drum 2, in braking contact with which are the blocks 3 of a brake lever being devoted drawing, which is a side.

band 4., The shaft and drum rotate counter- ClOCkW-ISG, as indicated by the curved arrow. The dead-end 5'of the brake-band, instead of being fixed (as is usual with non-different1 al band brakes), is pivoted. at 6, intermed1ate the ends of alever 7 whose fulcrum 8 is taxed in the supporting frame'9.

The other end of the lever 7 is pivoted in a block 10, carried by the piston rod 11 of a piston 12. F I

The live-end 13 of the brake-band is pivoted (as usual) at 14, intermediate the ends of a foot-lever '15, whosefulcrum 16 is fixed in the supporting frame.

The other end of the lever. 15 carries a pedal 17 and a reach-rod 18 which actuates an admission and release valve 19, by means of a crank 20. The words admission and release valve are used by us to designate a valve mechanism which operates after the manner of a. conventional three-way'valve. Steam comes through a pipe 21, the valve 19, and a pipe 22, to the cylinder 23 of the piston 12. This cylinder iscarried by the frame 9. The exhaust steam is carried away from the valve 19 through a pipe 24.

A compression spring 25 engages with a nut 26 on the end of the piston rod 11, and with a bracket 27, carried by the frame 9, thus tending to keep thev dead-end of the brake-band at all times released.

An adjustable stop 28 is provided, so that the motion of the lever 7 under the influence of the steam, will be just sufiicient to take up the slack in the brake-band 4, without applying any braking effect.

It may be seen, scription, that the first slight downward motion of the pedal 17 applies steam to the cylinder 23, thus taking up all the slack in the brake-band 4, and so enabling the remaining downward motion of the pedal to be devoted to increasing gradually the tension in the brake-band.

Conversely, upon the upward motion of the pedal 17, the brake-band is gradually slacked 0E, until finally it is released by the exhausting of the steam and the action, of the spring 25, atthe last partof the upward motion of the pedal.

The valve 19 is not shown in detail, such from the foregoing dethe art.

It is evident that any convenient form of control lever can be substituted for lever 15,

and other forms of stop, spring, cylinder,

band, etc., be used, any convenient means for taking out the slack be used, provided that this means is separate and distinct from the means which does the final setting of the brake, and many other changes he made, without affecting the spirit of our invention.

We claim: 1. In a brake, the combination of a rotating shaft, a brake drum thereon, a brakeband for frictional engagement with the drum, brake-controlling mechanism, means controlled thereby for setting and releasing the brake, and separate means controlled by said mechanism for taking up and restoring the slack inthe brake-band.

2. In a brake, the combination of a rotating shaft, a brake drum thereon, a brakeband for frictional engagement with the drum, brakecontrolling mechanism, means controlled thereby for setting and releasing the brake by motion of the live end of the brake-band, and separate means controlled by said mechanism for taking up and restoring'the slack in the brake-band by motion of the dead end thereof.

3. In a brake, the combination of a rotating shaft, a brake drum thereon, a brakeband for frictional engagement with the drum, brake-controlling mechanism, means.

controlled thereby for setting and releasing the brake by motion of the live end of the brake-band, and separate means controlled by said mechanism for taking up and restoringthe slack in the brake-band by motion of the'dead end thereof, said first named means consisting in a brake-lever. Y

4. In a brake, the combination of a rota ing shaft, a brake drum thereon, a brakeband for frictional engagement with the drum, means for setting and releasing the brake by motion of the live end of the brakeband, and independent means for taking up and restoring the slack in the brak eband by motion of the dead end thereof, said lastnamed means consisting in a fluid operated piston.

5. In a brake,'the combination of a rotating shaft, a brake drum thereon, a brakeband for frictional engagement with the drum; means for setting and releasing the brake by motion of the live end of the brakeband, and independent means for taking up and restoring the slack in the brake-band by motion of the dead end thereof, said first named means consisting in a brake-lever,

said last named means consisting in a fluid operated piston.

6. In a brake, the combination of a. rotat ing shaft, a brake drum thereon a brakerelease valve, and

operated piston, controlled by a part of the I motion of said brake-lever.

7. In a brake, the combination of av rotating brake-drnm a brake-band for frictional engagement with the drum, means for setting the bralie, and means for taking up the slack of the brake-band, comprising a fluidactnated piston, operating on the dead end of the brake-band.

8. Method of setting a brake-band, consisting in first taking up the slack in the band by means associated with its dead end, and then gradually tightening the band by means associated with its live end.

9. hIethod of releasing a brake-band, consisting in first gradually loosening the hand by means associated with its live end, andv then slackening the band by means associated with its dead end.

10. In a brake, the combination of a rotating shaft, a brake drum thereon, a brakeband for frictional engagement with the drum, means for setting and releasing the brake by motion of the live end of the brakeband and independent means: for taking up and restoring the slack in the brake-band by motion of the dead end thereof, said firstnamed means consisting in a brake lever, said last named means consisting" in a finid operated piston, controlled by a part of the motion of said brake-lever acting through an admission and release valve.

11. In a brake, the combination of a. rotating shaft, a brake drum thereon, a brake band for frictional engagement. with the drum, means for setting and releasing, the brakeby motion of the live end of the. brake,- band, independent means for up the slack in the brake-band by motion of the dead end thereof, said first named means consisting in a brake-lever, said last. named means consisting in a fluid operated piston, controlled by a part of the motion of said brake-lever acting through an admission and springmeansfor restorm' g the slack in the brake band.

12. In a brake, the combination of a rotating shaft, a. brake drum thereon, a. brakeband for frictional. engagement the,

drum, means for setting and relea the brake, independent means: fort restoring the, slack in the brakeeband, and adjustable means for preventing such taking-up of slack from producing braking effect. v

13. In a brake, the combination of a rotating shaft, a. brake dr fihgmon a by 1 band for frictional engagement with the band for frictional engagement with the drum, means for setting and releasing the drum, means for setting and releasing the brake, and separate means operating to take brake, and separate but associated means or 10 up and restore the slack in the brake-band taking up and restoring the slack in the 5 during each operation ofthe brake. brake-band. 14. In a bl'flk85 the combination of a rotat- FRANK WILKINSON.

ingshaft, a brake drum thereon, a brake- WERNER LE "In: 

